This report describes the provisions that were used to design and construct World Trade Center 1, 2, and 7. Included is a summary of the major provisions in the codes and standards together with the loads and load combinations that were used to design the buildings. Methods used to proportion structural members and other components of the buildings are also discussed, as well as tests that were performed to support the design. It is shown that the loads that were used to design the members were at least equal to those prescribed in the applicable codes and standards, and that the methods used to proportion the structural members followed the requirements in the applicable material design standards available at that time. Also included in this report are the innovative systems, technologies, and materials that were used in the buildings, and the Port Authoritys acceptance procedures for such items. Fabrication and inspection requirements at the fabrication yard and inspection protocol during construction are discussed. Also covered are the details of the deviations to contract documents that were granted by the Port Authority, including the justifications for those deviations.